Cleaning helical flights



United States Patent 72] Inventor Harold M. McCall Fairlnwn, New Jersey [2]] Appl. No. 688,951

[22] Filed Dec. 7, 1967 [45] Patented Nov. I7, 1970 [73] Assignee Raymond International, Inc.

New York, New- York a corporation of New Jersey [54] CLEANING HELICAL FLIGHTS 10 Claims, 4 Drawing Figs.

[5 6] References Cited UNITED STATES PATENTS 585,800 7/1897 Toulouse... l98'/229X 1,635,373 7/1927 Lofholm l98/229X Primary Examiner-Edward A. Sroka Attorney-Ward, McElhannon, Brooks & Fitzpatrick ABSTRACT: Cleaning of helical flights such as those on earth boring angers by mounting scraper elements on a freely rotatable wheel axis is transverse to the auger axis so that the longitudinal movement of the flights will produce corresponding movement of the scraper elements against and away from the flights.

Patented NW. 17, 1970 4 3,540,512

Sheet 1 of 3 0) INVENTOR.

Patented Nov. 17; 1970 I 3,540,572

Sheet 2 of 3 N S? Q1 E Q I 1 w Q mil W v E p9 $8 fi 3 (gel/ Y BY 4/7-0 Wv5 s Patented Nov. 17, 1970 1 CLEANING HELICAL FLIGHTS SPECIFICATION stem; and they have a cutter formation at one end which digs into the earth as it is turned by the stem. Generally the cutter formation comprises one end of one or more helical flights which wind back around the stem. The helical flights serve as conveyors for the earth which is loosened by the cutter; so that this earth may be removed up from the hole being dug.

- Very often, especially where the earth has a high clay content, the spaces between successive flights along the length of the auger become packed with earth; and it is consequently necessary to stop the boring operation while the auger is removed and the accumulated material is cleaned from among its flights. This cleaning operation is often difficult and time consuming.

Prior devices for cleaning auger flights utilized scraper elements mounted rigidly on a framework. The auger to be cleaned was either rotated through the scraper elements or it was gradually rotated and adjusted so as to bring successive regions to be cleaned into position in front of the scraper elements; and these would be worked, usually by hand, into the clay or other material to be removed. It was not possible to use simple scraper elements which moved along the auger since the configuration of the helical flights of the auger would in terfere with the movement of the scraper, unless of course, the rotational and axial movements of the auger were precisely coordinated.

The present invention permits the cleaning of helical flights in a very rapid and efficient manner without requiring hand working and without requiring special coordination of the axial and rotational movements ofthe device being cleaned.

According to one aspect of the present invention a plurality v of scraper elements are maintained spaced from each other and these scraper elements are caused to be brought against the device while it is rotated about its helical axis. During this rotation the scraper elements are restricted from movement in the rotational direction of the device but they are permitted to move freely in the axial direction.

According to a further aspect of the present invention there is provided a plurality of scraper elements distributed uniformly about the axis of rotation of a freely rotatable support member. The scraper element pitch, i. e. the circum-- ferential distance between adjacent scraper elements is chosen to be substantially equal to the flight pitch of the device to be cleaned. The support member is mounted withits rotational axis transverse to the helical axis of the flights to be cleaned with at least one scraper element extending between successive flights to effect scraping thereof as the auger or other helically flighted device is rotated. Should the device merely be rotated without accompanying axial movement, then the surface of the flights will 'move in the axial direction of the device and will tend to move the one scraper element in the same direction. This will cause the support member to rotate however so that a new scraper element will be brought between the next successive flights to effect further cleaning. Of course, any axial movement of the device being cleaned will automatically be accommodated in the same manner.

Further specific features and advantages of the invention FIG. 4 is a front elevational view of a modified form of the auger cleaning device of FIG. 1.

In FIG. 1, an auger cleaning device 10 according to the present invention is mounted on a support frame 12 in position'to effect cleaning of an earth boring auger l4.

The earth boring auger 14 comprises an elongated center shaft 16 about which are arranged helical flights 18. The axis of thehelical flights 18 coincideswith the longitudinal axis of the center shaft 16. The auger I4 is mounted by means of the support frame 14 in a vertical position to pass through an outer shell 20 and down into the earth. Means (not shown) are provided to rotate the auger 14; and as it digs into the earth it moves downwardly. The helical flights 18 aid in bringing earth, [.e. mud, clay etc. out of the hole which is being dug.

During the digging operation, depending upon the nature of the earth being dug, more or less of it will cling to the auger and clog the spaces between adjacent flights. This disrupts r Turning now to'FIG. 2, it will be seen that the individual scraper disks 22 are heldto the star wheel 24 by means of bolts 26. Holding nuts 28 are threaded onto the bolts 26 and are held in place by cotter pins 30. Spacer washers 32 are provided between the scraper disks 22 and the star wheel 24 to permit rotation of the disks with respect to the star wheel.

The star wheel 24 is bolted to a hub 34 and this in turn is secured by means of tapered roller bearings 36 and 38 to a spindle 40. The spindle 40 extendsout from a pivot member 42 which is pivotally mounted on the end of a mounting arm 44 on the support frame 12. The pivot axis of the pivot member 42 is perpendicular to the rotational axis of the star wheel 24.

A bias arm 46 extends out laterally from the pivot member 42; and a biasspring 48 is connected between the outer end of the bias arm and the support frame 12. This arrangement, as seen in FIG. 2 serves to urge the assembly in a counterclockwise direction about the pivot axis of the pivot member 42.

The assembly is mounted on'the support frame 12 in a position such that the outermost edge of one of the scraper disks 22 rests tangentially against the surface of the center shaft 16 j between adjacent flights 18 of the auger 14 as shown in FIG.

2. The bias spring'arrangement thus serves to maintain the scraper disk 22 pressed against the auger l4. As the auger rotates in a clockwise direction, Le. toward the scraper disk 22, digging material (indicated at 50) will be scraped off the auger.

r Operation of the above described device can best be un-' derstood from a consideration of FIG. 3. As the auger l4 rotates against the cleaning device 10 as above described, its

flights I8 progress upward or downward (depending upon the direction of auger rotation) with respect to the cleaningv device. This upward or downward movement will urge the contacting scraper disk 22 in a corresponding direction. This action produces-rotation of the star wheel 24 and brings a successive one of the scraper disks up into scraping position against the auger. Because of the fixed spacing between the successive disks, the subsequent disk will contact the auger center shaft on the opposite side of the flight l8 contacted by .the first disk. Thus, as the auger continues to rotate, each of the spaces between successive flights 18 along the length of the auger, will be scraped by successive ones of the various scraper disks 22. Further, because of the freely rotatable star wheel and disk arrangement, the flights themselves on the auger control the movement of successive disks into and out of scraping position.

' speed or direction movement is required. Thus, cleaning may be effe.

It will be appreciated that with this arrangement each individual disk is in scraping position only a relatively short time. As a result, the disks do not become overloaded with scraping material; and when they are brought away from the auger this material is readily discharged off from the disk.

The actual spacing between the successive scraper disks 22 (i.e. the pitch of the star wheel 24) should be such that each disk is brought into scraping position at a location between adjacent auger flights, so that the disks do not bind up on the flights. It has been found preferable to maintain the disk to disk spacing or star wheel pitch (indicated at P, in FlG. 3) approximately equal to the helical pitch (indicated at P in FIG. 3) of the auger l4.

It is possible to employ shapes other than disks for the scraper elements of the present invention. In the modified arrangement shown in FIG. 4 there are provided shovel-like scraper elements 54 distributed about a central supporting disk 56. The central supporting disk 56 is rotatably supported in the same manner as the star wheel 24 of the preceeding embodiment. The scraper elements 54 are each mounted to pivot about mounting pins 58 near the periphery of the disk 56. An inner arm 60 on each element 54 is positioned between two stop pins 62 to limit the extent of this pivotal movement; and a bias spring 64 urges the element 54 to a position such that its arm 60 rests against one of the pins.

The scraper elements 54 include a bottom portion 66 which, as shown in FIG. 4 scrapes against the surfaces-of the flights 18 of the auger. The scraper elements also include a side portion 68 which scrapes against the center shaft 16 of the auger.

The manner of operation of the arrangement of FIG. 4 is generally similar to that of the arrangement of FIGS. 13. Thus, as the auger l4rotates, its flights 18 act upon the various scraper elements 54 to move them up or down and this serves to rotate the supporting disk 56 to bring a new scraper element into scraping position. The spring biasing of the individual scraper disks compensates for geometric disparities between the auger 14 and the cleaning device. it also ensures that the scraper elements 54 always press against the auger surfaces. While the circular configuration of the disks 22 of the preceeding embodiment permitted compensation for any geometric disparities between the auger and the cleaning device, that arrangement required that the disks touch the auger center shaft at a tangent point to obtain optimum cleaning. This positioning is not required with the arrangement of FIG. 4.

it will be appreciated that in each embodiment described, the auger flights themselves serve to move the individual scraping elements in a generally longitudinal direction so that they successively move into and out of contact with the flights to effect the desired cleaning action. This longitudinal movement of the scraper elements depends upon the helical pitch of the auger flights as well as upon the relative rotational velocity and longitudinal or axial movement of the auger. ln

any event, the scraper elements are free to move as required by the auger flights so that no special coordination of either of auger rotation and longitudinal auger er during raising or lowering of the auger and during either forward or reverse rotation thereof.

Having described the invention with particularity with reference to the preferred embodiment of the same, and hav-- ing referred to some of the possible modifications thereof, it will be obvious to those skilled in the art, afterunderstanding the invention, that other changes and modifications may be made therein without departing from the spirit and scope of the invention and the appended claims are intended to cover such changes and modifications as are within the scope of the invention.

I claim:

1. A method for cleaning an earth boring auger having helithe steps of rotating said flights about their helical axis; simul taneously moving said auger m a direction along its longitudinal axis; and during said rotation and longitudinal movement holding scraping means against the rotation of said flights by maintaining said scraping means in a position lying tangentially against said stem whereby material to be removed is scraped off said flights by said scraping means, while allowing said scraping means to be moved by said flights in a generally longitudinal direction therealo'ng whereby said flights are cleaned of material tending to adhere thereto along the length of said auger.

2. A method as in claim 1 wherein said scraping means are so moved as to be brought successively into and out of contact with said flights.

. 3. A method as in claim 1 wherein said scraper means comprise a plurality of scraper elements and wherein said scraper elements are individually and successively brought into and out of contact with said flights.

4. Apparatus for cleaning helical flights, said apparatus comprising a plurality of scraper elements and mounting means constructed to hold said elements against movement in a first direction in opposition to the rotation of such flightsbut to permit free movement of said elements in a second, transverse direction generally longitudinally of said flights, said mounting means including spring biasing means constructed to urge said scraper elements against said flights.

5. Apparatus as in claim 4 wherein said scraping elements are maintained at fixed distances from each other. I

6. Apparatus as in claim 5 wherein said scraping elements are arranged in conjunction with said mounting means so as to be successively moved into and out of scraping position longitudinally on said flights.

7. Apparatus as in claim 4 wherein said scraping elements are freely rotatable on said support member.

8. Apparatus for cleaning helical flights, said apparatus comprising a plurality of scraper elements and mounting means constructedto hold said elements against movement in a first direction in opposition to the rotation of such flights but to permit free movement of said elements in a second, transverse direction generally longitudinally of said flights, said mounting means comprising a rotatable support member having said scraper elements distributed about its axis of rotation, said rotatable support member being mounted for pivotal movement about a further axis transverse to its rotational axis, said-rotatable support member being spring biased to a fixed rotational position about said further axis.

.9. Apparatus as in claim 8 wherein said mounting means comprises a common mounting member upon which said scraper elements are mounted in succession along a given path and means restricting the movement of said common mounting member so that said scraper elements move only along said given path.

10. Apparatus as in claim 8 wherein said scraper elements are in the form of disks UNITED ST A'IES PATENT OFFICE 9 CERTIFICATE OF CORRECTION Patent No. 5 1 Dated November 17, 1970 Inventor(s) Har0ld M. McCall It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 58, delete "effe er' and substitute the words --effected either Signed and sealed this 13th day of April 1971 (SEAL) Attest:-

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER Attesting Officer Commissioner of Pat 

